Psychometric tests are standardized tests used to measure mental performance in areas like verbal ability, personality, employment interests, values, attitudes, and motivation. There are two main types - tests that measure maximum performance and tests that measure typical performance. Selection processes often involve general intelligence tests to check IQ level, attainment tests to evaluate knowledge usage, and aptitude tests to determine natural ability. Test results are analyzed using minimum cut-offs and candidate profiles to facilitate top-down selection.